No long-term ischemic risk with 1-month DAPT after PCI in high-risk patients
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In adults with high bleeding risk, early deintensification of dual antiplatelet therapy after PCI was associated with less bleeding and no increased ischemic risk beyond 12 months vs. standard treatment, according to a speaker.
Presenting new 15-month data from the MASTER DAPT trial at the European Society of Cardiology Congress, researchers also found that during routine care, prior allocation to standard treatment was a major driver for more intense antiplatelet therapy beyond 1 year. Ischemic risk — but not bleeding risk markers — also affected the decision making of continued intensified long-term antiplatelet therapy.
“The extra 3 months of follow-up are when clinicians decided to treat patients the way they wanted,” Marco Valgimigli, MD, FESC, deputy chief of interventional cardiology at Cardiocentro Ticino Institute, Lugano, Switzerland, told Healio. “We took that extra phase into account when planning MASTER DAPT because we thought all patients would stop DAPT after 12 months and we would see the treatment effects after all groups stopped. The big surprise was that was not the case. There was an incredible proportion of patients in the control group which continued DAPT beyond 1 year. If you consider that we selected only patients at high bleeding risk, and guidelines state DAPT should never exceed 6 months in high bleeding risk, and some patients should not exceed 1 week, that is an incredible finding.”
A trial ‘carryover effect’
As Healio previously reported, MASTER DAPT showed that DAPT for 1 month after PCI lowered bleeding rates and was noninferior for ischemic events compared with 3-month DAPT among participants at high bleeding risk. Researchers randomly assigned 4,579 patients (mean age, 76 years; 69% men) at high bleeding risk who underwent PCI with a biodegradable-polymer sirolimus-eluting stent (Ultimaster, Terumo) to 1 month or at least 3 months of DAPT. Randomization occurred 1 month after PCI, after which the abbreviated therapy group stopped DAPT and the standard therapy group continued DAPT for at least 2 more months. DAPT consisted of aspirin and a P2Y12 inhibitor; single antiplatelet therapy consisted of either of those.
The study included three ranked primary outcomes: net adverse clinical events, defined as all-cause death, MI, stroke or major bleeding; MACCE, defined as all-cause death, MI or stroke; and major or clinically relevant nonmajor bleeding.
After 12 months, participants in both arms received routine clinical care. Researchers recorded medications and adverse events during the following 3 months; complete follow-up data at 15 months was available for 99.8% and 99.9% of patients in the abbreviated and standard arms, respectively.
At 15 months, net adverse clinical events occurred in 8.7% and 9.5% of participants in the abbreviated and standard DAPT groups, respectively, for an HR of 0.92 (95% CI, 0.76–1.12; P = .399) and a risk difference of –0.75 percentage points (95% CI –2.42 to 0.93).
MACCE occurred in 6.9% and 7.4% of participants in the abbreviated and standard DAPT arms, respectively, for an HR of 0.94 (95% CI, 0.76-1.17; P = .579), for a risk difference of –0.51 percentage points (95% CI, –2.01 to 1).
Major or clinically relevant nonmajor bleeding remained lower in the abbreviated compared with the standard therapy arm (7.4% vs. 10.7%; HR = 0.68; 95% CI, 0.56-0.83; P = .0001), for a risk difference of –3.25 percentage points (95% CI, –4.93 to –1.58).
“We saw a carryover of the treatment effects at 1 year, meaning there was no between-group difference for MACCE,” Valgimigli said in an interview before the meeting. “Net clinical adverse events were numerically already in favor of abbreviated treatment at 1 year; this was even more so at 15 months. There was a larger between-group difference in bleeding at 15 vs. 12 months. That is because despite that [extended DAPT treatment] was not expected during the routine care phase of the MASTER DAPT study, there was a continued treatment contrast between abbreviated and standard treatment arms. That is why the results became even clearer than they were at 1 year.”
‘Bleeding risk should dominate ischemic risk’
Guidelines recommend patients not on oral anticoagulation should discontinue DAPT; however, more than 15% of participants not on oral anticoagulation were still on DAPT at 15 months in the standard DAPT arm, Valgimigli said during a press conference.
Similarly, although guidelines recommend patients prescribed oral anticoagulation should discontinue single antiplatelet therapy if free from recurrent ischemic events or repeat interventions, more than one-fourth were still on single antiplatelet therapy in the standard DAPT arm compared with 14% of the abbreviated treatment group.
In a multivariate model, researchers found that prior allocation to abbreviated treatment was a strong independent predictor of single antiplatelet therapy vs. DAPT among participants not on oral anticoagulation therapy and no antiplatelet vs. single antiplatelet therapy among participants on oral anticoagulation therapy.
“We also looked into the drivers — why did clinicians choose to continue DAPT?” Valgimigli told Healio. “Interestingly, that decision making was driven by the perceived ischemic risk of the patient on clinical grounds. So, diabetes, HF. Not PCI complexity. Bleeding risk features did not play any role in the decision making. This is a mindset that needs to be changed. We have evidence showing that bleeding risk takes a toll. The bleeding risk should dominate ischemic risk in decision making with respect to DAPT duration. In practice, it is absolutely the opposite. Ischemic risk dominates the bleeding risk. People do not even assess bleeding risk.”
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Valgimigli M, et al. Hot Line 8. Abstract Number or Session Name. Presented at: European Society of Cardiology Congress; Aug. 26-29, 2022; Barcelona, Spain (hybrid meeting).
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